1. Field of Invention
The invention relates to pumps and more particularly to such a pump with improved characteristics.
2. Description of Related Art
Positive-displacement pumps for transporting fluids are known in the art. The pump comprises a periodic displacer, a piston or diaphragm, and two passive check valves. Due to the periodic movement of the piston or diaphragm, liquid is drawn into a pump chamber through an inlet valve and displaced from the pump chamber through an outlet valve. Due to the use of these valves, the conventional pumps are complicated and expensive. Moreover, the direction of transport is predetermined by the arrangement of the valves. When the pumping direction of such an arrangement is to be reversed, such pumps require a change of the operating direction of the valves from outside which entails a high expenditure.
Further, a type of pump having a small constructional size and delivering small pumped streams is referred to as micro-pumps. The invention described later is directed to a miniaturized pump with improved characteristics.